Mixing device



Dec. 28 1926.

B. 'GRANVILLE MIXING DEVICE Filed NQV. 17

yIIIIIIIIIIIIIIIIIHJ application to the class of.. suc

Patented Der. 2s, 1926.

UNITED vSTATES BERNARD GRANVILLE, F NEW YORK, N. Y.

ilrxme DEvIcE.

Application med November 17, 1920. .Serial No. 424,609.

This application relates to devices for mixing a liquid with a gas, andhas articular devices known as carbureters which are used in connectionwith internal combustion engines to mix liquid fuel with air.`

An object of the invention is to provide a device in which theproportion of liquid mixed with the gas is automatically determined bythe rate of low of gas through the device.

A ,further object of the invention is to improve and sim lify themechanism for operating the va ve controlling the admission of liquid tosuch a device.

YWhen applied to the carbureters of internal combustion engines, theinvention affords a means whereby .the proportionv of fuel vapor in themixture drawn into the engine is automatically controlled by the speedof the engine.

According to my invention, the percentage of liquid fuel in the form ofvapor mixed with the air drawn .through the carbureter is regulated by abalancing of liuid pressures. The device contains no valves and nomoving parts other than a iioat, and is thus not sub'ect to theirregularities in action which ave characterized mechanical devices forregulating the richness of the mixture. Furthermore, in accordance withmy invention, the richness of the mixture may be maintained constant, orotherwise regulated, 'throughout the entire range of the engine Speedand the device may, therefore, be so adjusted as to produce preciselythe most eyiicient mixture at all speeds of the engine.

In carrying out the invention, I divide the liquid receptacle-of thecarbureter so as to provide two balanced columns of liquid. In the airpassage of the carburetor I provide a Venturi tube in which the fuelnozzle is located, and a Pitot tube communicating with the liquidreceptacle above one of the columns of liquid therein. Located in theother column in the liquid'receptacle is a float which carries thenozzle. e

In order that my invention may clearly be understood, I will describe indetail the carbureter embodying the invention which isshown in theaccompanying drawings, in

' which va source `of liquid fuel.

Fig. 2 is a transverse section taken on the line 2-2 of Fig. 1;

Fig. 3 is a transverse section taken on the l1ne' 3--`3 of Fig. 1;

Fig. 4 is a fragmentary section sectioned on a plane at right angles tothe section plane of Figal showing a means for adjusting the position ofthe Venturi tube in the airv channel; and

Fig. 5 is a top View of the nozzle and the iloat on which it issupported.

The carbureter shown in the drawing comprlses a liquid receptacle andanair passage 11 separated by a partition 26. The mtake end 12 of thechannel 11 is opento the atmosphere or, if desired, is connected by aplpe to a source of warm air. The outlet end 13 of the channel 11 isconnected tothe .intake manifold of the engine. In the channel 11 is abutterfly throttle valve 14 of ordinary construction. From an aperturein the bottomof the liquid receptacle extends an elbow pipe 15 to theouter end of which is connected a pipe leading from The elbow 15 ismaintained in position by a collar 16 screwed upon a boss 17 at thebottom of the carbureter. A channel 18 leads from the liquid receptacle10 to a point in the channel 11 near the end of the butterfly valve 14.This channel is .controlled by a manually operated valve 19 and servesto permit the drawing ofliquid fuel directly into the upper portion ofthe channel 11 when the butteriiy valve is almost closed, to aid instarting the engine. The parts thus far de- ,scr1bed are in common usein carbureters.

An apron extends into the liquid receptacle 10 from the partition 26.The apron 25 divides the liquid in the liquidreceptacle 10 into twobalanced columns, an outer annular column 27 anda central column 28 ofmuch smaller cross-sectional area than the column`27. Means are providedfor maintaining constant the height or level of the outer column 27.These means include an annular iloat 29 in the column 27, a valve 30controlling the admission of liquid to the liquid receptacle through theelbow 15,' and two levers 31. The valve 30 is normally seated by its ownweight upon a conical seat 32 in the inner end of the elbow 15. The

valve is maintained in alignment with the seat by a stem 33 which entersa blind hole 34 in the elbow 15. The upper portion ofv the valve 30 isprovided with a transverse slot 35 Fig. 3) in which lie the inner endsof the levers are pivoted upon a pin 36 extending through the valve 30and aci-oss the slot 35;

Each of the levers 31 has at an intermediate passes/through the Venturitube 50 its vepoint at its lower side an integral projection 37 whichrests upon the bottom of the liquid receptacle 10 and serves, as thefulcrum of the lever. Each lever is provided with an upward projection38 at the outer end of its upperside.

In the column 28 is a float 40 which extends upwardly into the channel11 through a central aperture 41 in the partition 26. The float 40 bearsat its upper end a nozzle 42 containing a passage 43 which communicateswith a small pipe 44 extending through the float 40 and communicating atits lower end with the liquid in the liquid receptacle 10. lower portionof the float 40 incentral posiv tion within the vapron so that the'upperatmospheric pressure. The air in the chan- A portion of the float doesnot bind in the aperture 41.

i A Venturi tube 50 is located in the channel 11 in such position thatthe end of the nozzle 42 lies within it. The Venturi tube 50-is providedwith a cylindrical flange 51 which lits within the upper portion of thechannel 11.. Fromtheflange 51 projects a stud 52 which passes through alslot 53 in the Wall of the channel 11 (Fig. 4). On the outer end of thestud 52 is screweda nut 54. The arrangementdescribed permits a verti-`cal adjustment of the Venturi tube 50 in the channel 11. i

A Pitot tube 55 is screwed into a threaded hole 56 in the partition 26above the top of the column 27. The Pitot tube 55 extends into thechannel 11 and its outer end 57 is r passing valve 30 in order to floodthe carbureter i to facilitate starting the engine.

The rod 60 may conveniently be .extended into the liquid receptacle 10through they Pitot tube 55 as shown in Fig. 1. A spring 61 maintains therod 60 normally in raised position.

The operation of the device described is as follows It will beunderstood that before a current of air is drawn through theV channel 11this channel is lled with air at nel has free access to both the columnsof liquid in the receptacle 10, reaching the column 27 through the Pitottube 57 i and the column 28 through the aperture 41 in which the float40 lits loosely. The device is placed in operation by reducing thepressure at the out-let end 13 of the channel 11, the reducf tion ofpressure being usually caused by the suction created in the cylinders ofan interevers 31. The inner ends :of the A lange 45 (Fig.` 5) maintainsthe.

nal combustion engine with which the device is used. Because of thisreduction of ressure at the outlet end 13 the atmosp eric pressureapplied at the entrance'end 12 of `the channel 11 causes' a` current ofair to the receptacle 10 to pass through the pipe 44. As the result theliquid is sprayed into the air in the Venturi tube through the nozzle43. The rate at which liquid is projected through the nozzle is, ofcourse, dependent upon the difference between the pressure applied tothe column 28 and the pressure in the portion of the Venturi tube 50 inwhich the nozzle' 43 is located. It follows that when the end ofthenozzle 43is in the narrowest portion of the Venturi tube `50 the suctionand the consequent rate of flow of liquid through the nozzle is greaterthan when the end of the nozzle is located in a wider portion of theVenturi tube. The position of the nozzle 42 in the Venturi tube isautomatically determined by the rate at which air is suckedv through thechannel 1l by the engine. 'The current of air through the channel 11produces in the Pitot tube a pressure which increases as the velocity ofthe current increases. This pressure is applied to the top of the columnof liquid 27, while thepressure applied to the top of the column'28through the central opening 41 is not inereasedwith an increase in thevelocity of the current. The diierence in the pressure applied to thetwo columns consequently causes a difference in the height of thecolumns, which difference is increased as the pressure increases. As thelevel of the column- 27 4is maintained substantially constant by thecontrol of the valve -30 by the `float 29, the pressure results in anincrease in the height of the column 28. \As the liquid in the column 28rises, the float 40 is carried upward, raising the nozzle 42. The end ofthe nozzle is thus brought into a wider portion of the Venturi tube50 sothat the rate at which the liquid is drawn through the nozzle ismaintained in exact proportion to the flow of air, maintaining constantthe richness of the mixture drawn into the lengine.

The height to which the level of the column 28 is raised above the levelof the column 27 depends not only upon the pressure produced by thePitot tube but also upon the J i l jsure `produced by the Pitot tube.

It is apparent that by proper proportion'- 4ing of the opening in thePitot tube 55, thearea of the columns 27, 28 and the position andshapeof the Venturi tube 50, the device may be arranged so asautomatically to produce just the mixture desired for every lvelocity offlow of air through the channel 11, that is to say, for every speed ofthe engme. rlhe- Adevice affords numerous advantages besides thosehereinbefore referred to. vThus the central location of the column 28with respect to the column 27 enables the devlce to operate wheninclined at a considerabley drawings, and it should be understood,

therefore, that the use of the word.pres sure in the claims heretoappended is intended to include a negative pressure as well as apositive pressure.

The Venturi tube may be located anywhere in the channel through whichthe gas passes and may be formed asan integral part of the channelinstead of as a separate piece as shown. The expression chanv nelincludmg a Venturi tube usedin the accompanying claims is intended toinclude any means Whether or not integral with the wall of thechanneljwhich provides, inthe channel, zones of dilerent cross-sectionsat which the velocity/ of the current will be diiierent. I

While the combination of the Pitot and Venturi tubes eliminates allvalvesand pro'-V duces most desirable results, either of these devicesmay advantageously be used separately. Thus the pressure produced by thePitot tube may be utilizedv to operate a valve or otherwise control therate at which the liquid is drawn-from the rece tacle 10 without the useof the Venturi tu e 50. Or, on the other hand, other means than thepressure produced by the Pitot tube 55 may be used to position the`nozzle 42 in dierent parts of the Venturi tube 5 0. A

While I have found the arrangement of the apron- 25 and the floats 29and 40 satisfactory and convenient, it is nevertheless true that thisarrangement may be var1ed' as, for example, by applying the pressureproduced by the Pitot tube directl to the column of liquid whose heightregu ates the position of the nozzle 42. or by reversm thc connectionsof the two floats. The nozz e 42 need not be borne directly upon one ofthe floats, but may be operated by one of 4'the floats by means of a rodor other connectlon.

'lhe invention is not limited to its application to the carbureter of aninternal combustion engine,-but may be availed of wherever it is desiredto regulate the proportions of a mixture of a liquid and a gas..

What is claimed is:

l. In a device for mixing a gas and a liquid, the combination of achannel including a Venturi tube through which the gas is passed, aliquid receptacle arranged to divide the liquid into balanced columns, apassage *for the liquid from said receptacle to said channel, a nozzleat the end of said passage located in said Venturi tube, a Pitot tubecommunicating with said receptaclefextending into said channel andadapted to apply to one of said columns a pressure determined by therate of llow of gas through said channel,'means for retaining the heightof one of. said columns substantially con-- stant, means for varying thelocation of said nozzle in said Venturi tube actuated by variations inthe height of the other of said columns produced by said pressure.

2. In a device for mixing a gas and a liquid, the combination of achannel including y a Venturi tube through which the gas is passed, valiquid receptacle adapted toA divide the liquid into balanced columns, apassage for they liquid'from said liquid receptacle to said channel, anozzle at the end of said passage having its end located in said Venturitube, a Pitot tube co'mmunicating'with said liqluid receptacle,extending into said channe and adapted to apply to one of said columns apressure determlned by the velocity of flow of O'as through said.channel, means for maintaining the height of said column substantiallyconstant, and a float in the other of said .columns arrangedto vary theposition of said nozzle in said Venturi tube as the height of saidcolumn varies under the influence of said ressure.

In testimony w ereof I havehereunto set my hand.

BERNARD GRANVILLE.

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